The present invention relates to wafer lot identity management technology, and more particularly, to a method and system of wafer lot identity conversion.
During semiconductor manufacturing, the semiconductor wafer passes through a series of process steps, which are performed by various fabrication tools, such as photolithography, chemical-mechanical polishing, or chemical vapor deposition. For example, in the production of an integrated semiconductor with 15 micron product, the semiconductor wafer may pass through up to 600 process steps.
Integrated circuits are typically fabricated by processing one or more wafers as a “lot” with a series of wafer fabrication tools (i.e., “processing tools”). Wafer lot identities (ID) are provided to monitor and control the wafer lots among various fabrication tools and automated systems via a manufacturing execution system (MES) or a management information system (MIS) A client may use the wafer lot IDs to query processing status, projected finish date, engineering data or directly execute limited process control, such as holding a wafer lot or banking a wafer lot. The wafer lot ID is composed of multiple characters and may be encoded with reference to a manufacturing fab, lot created date or sequence number. Suppliers or clients may respectively employ proprietary encoding rules to identify their wafer lots.
Conventionally, an operator must use a supplier lot ID but not a client lot ID to acquire relevant manufacturing information or execute process control via systems provided by a supplier. The operator must convert the client lot ID to the supplier lot ID according to a mapping sheet. The labor-intensive nature of lot ID conversion using conventional means is detrimental to client satisfaction. Additionally, negligence in lot ID conversion can result in execution of the wrong process control or failure to acquire correct manufacturing information.
In view of these limitations, a need exists for a system and method of wafer lot ID management that increases client satisfaction in information acquisition and process control.